Research On PAM-based Drive And Control Method Of High-speed Permanent Magnet Synchronous Motor

High-speed permanent magnet synchronous motor is widely used in highspeed motorized spindle system because of its advantages of high power density,high efficiency and fast response speed.The small inductance and large fundamental frequency of high-speed PMSM will cause serious harmonic problems of stator current.At the same time,the bottleneck of computing power of microprocessor and the limitation of switching frequency output of power devices restrict the development of high-speed motor drive controller,which brings great difficulties to the stability of speed control of high-speed PMSM.In order to solve the problem of speed stability of high-speed motor in high speed operation,this paper presents a PAM-based driving control method for highspeed motor.The driving topology circuit,speed control method and sensorless phase displacement optimization of PAM are analyzed and studied.Firstly,the drive control strategy of high-speed motor based on PAM is proposed.The PAM square-wave driving method is given,and the sensorless control and start-up method are analyzed.The current model of square-wave current driving permanent magnet synchronous motor is established.The overall simulation model of PAM mode is constructed.The current ripple,harmonic and loss of high-speed motor system under different driving topologies are compared and analyzed.Secondly,the influence of the change of the parameters of the pre-BUCK circuit on the motor driving performance and the speed control method are studied.The small signal model of BUCK circuit is established.The commutation instantaneous current resonance and bus voltage fluctuation caused by improper selection of inductance and capacitance are analyzed.At the same time,in order to take into account the robustness and tracking performance of high-speed motor,a two-degree-of-freedom speed control method is developed to optimize the following performance and anti-disturbance performance of speed loop.Thirdly,the optimization of sensorless phase replacement is studied.The output torque and current harmonics of high-speed motors with different displacement phases are analyzed,and the method to find the optimal displacement phase is given.The causes of the errors are analyzed,and the detailed process of 90-? compensation method for the displacement phase error of high-speed motors is given.The relationship between neutral point voltage and displacement phase is deduced,and the displacement phase based on virtual neutral point voltage integral is proposed.The position closed-loop control method is simulated.Finally,the hardware circuit and software algorithm of the control system are designed,and an experimental platform is built to verify the effectiveness of the control strategy based on PAM.